Electrochemical electronics is known from e.g. WO03/047009A1, which is referred to for a closer understanding of this technology, and the entire contents of which is hereby incorporated herein by reference.
Just like in other types of electronic devices, there is a need for controlling (i.e. starting or stopping) a current flow in a circuit.
Conventionally, the control of the currents within a circuitry of electrochemical electronics has been performed by applying and removing an electric voltage/current to the polymer based electrical component. One way of controlling the voltage/current is to electronically couple and drain a battery, which battery is arranged such that enough voltage is applied to the electrical component for a sufficiently long time. Another way is to use a mechanical switch e.g. a membrane switch, or an IC controlled switch e.g. a capacitive push button.
One example of such a mechanical switch is provided in U.S. Pat. No. 5,912,759, which discloses a switch arm comprising a metal film, which subsequent to removal of a protective tape connects two electrodes.
A disadvantage with this switch is that it is complicated to manufacture and to operate, in particular with respect to the application and removal of the protective tape.
U.S. Pat. No. 5,763,058 discloses another type of switch, wherein the electrodes are placed on top of each other, separated by a fragile or resilient insulating layer having a plurality of holes or voids therein. When a force is applied to the electrodes, the insulating layer is broken or deformed, so as to allow contact between the electrodes.
The switch disclosed in U.S. Pat. No. 5,763,058 requires two layers of conducting material and one layer of insulating material to be deposited onto the substrate. Hence, it requires at least three production steps.
Other types of known switches comprise membrane switches or switches controlled by integrated circuits, such as capacitive push buttons etc. Stopping currents has been achieved by draining batteries, e.g. using mechanical switches coupled to many small batteries in parallel.
One known electrolytic switch is disclosed in U.S. Pat. No. 4,084,511, which describes an electrolytic timing element, wherein the degrading oxidation of the anode in an electrolytic liquid releases a spring, which activates the switch to arm a mine.
However, all of these solutions require more or less complicated structures, which are not easy to realize in a printing process or in a reel-to-reel process.